Bovine PrPC directly interacts with αB-crystalline

AbstractWe used a bovine brain cDNA library to perform a yeast two-hybrid assay with bovine mature PrPC as bait. The screening result showed that αB-crystalline interacted with PrPC. The interaction was further evaluated both in vivo and in vitro with different methods, such as immunofluorescent colocalization, native polyacrylamide-gel electrophoresis, and IAsys biosensor assays. The results suggested that αB-crystalline may have the ability to refold denatured prion proteins, and provided first evidence that αB-crystalline is directly associated with prion protein

First-principles study of O-2 activation on ligand-protected Au-32 clusters

NSFC [20873088]; Open Funds of State Key Laboratory of Physical Chemistry of Solid Surfaces (Xiamen University) [201109]; Fundamental Research Funds for the Central Universities, Southwest University for Nationalities [11NZYBS07]Poly(N-vinyl-2-pyrrolidone) (PVP) is often used to protect active Au clusters from coalescence. The influences of PVP on the O-2 adsorption on Au-32 clusters were investigated using density functional theory calculations. Various low-lying structures of O-2:Au-32 and O-2:Au-32:PVP complexes, in which the Au-32 is either neutral or anionic and the O-2 is either molecular or dissociative, were identified. The PVP influences were evaluated in terms of the changes in geometry, adsorption energy, charge redistribution, spin density, and density of states upon PVP pre-adsorption. Our calculations reveal that PVP weakly adsorbs on the cluster surface, with rather small changes in the structural, geometrical and electronic properties that are relevant to the O-2 activation. The activity of neutral or anionic Au-32 towards O-2 is kept or slightly enhanced by PVP because of the cooperative adsorption of PVP and O-2. This is the structural basis of choosing PVP as the protective ligand for Au clusters

Identification and characterization of a ribose 2′-O-methyltransferase encoded by the ronivirus branch of Nidovirales.

Peer reviewe

Near-field coupling and SERS effects of palladium nanoparticle dimers

The linear optical properties and the surface-enhanced Raman scattering (SERS) effect of spherical palladium nanoparticle dimers are analyzed theoretically using generalized Mie theory. The calculation results demonstrate that the near-field coupling effect greatly influences the absorption, scattering and extinction spectra of nanoparticle dimers. The surface plasmon resonance wavelength red-shifts dramatically as the separation between nanoparticles decreases. Because of the near-field coupling between nanoparticles and the size effect, the maximum SERS enhancement factor at the' hot spot' between palladium nanoparticle dimers is as high as 10(7)-10(8), while the averaged SERS enhancement factor over the entire nanoparticle surface is in the range of 10(5)-10(6). The deviation between the position of the peak in the extinction spectrum and the wavelength for maximum surface-averaged enhancement for the Pd nanoparticle dimers indicates that localized surface plasmon resonance has different influences on the far and near fields. These theoretical results may help to reveal the relationship between the far and near fields, as well as understand the mechanism of electromagnetic enhancement in the surface-enhanced scattering of transition metals.National Natural Science Foundation of China [20703032]; National Basic Research Program of China [2009CB930703]; Natural Science Foundation of Fujian Province of China [E0710028